This invention generally relates to an automatic accompaniment playing device for use in an electronic musical instrument which is capable of sequentially reading out prestored accompaniment pattern data to automatically generate an accompaniment tone such as a chord component tone, bass tone or percussive tone based on the pattern data.
In an accompaniment playing device of the above-mentioned type, as disclosed in for example Japanese Utility Model Laid-open Publication No. Hei 1-101299, plural accompaniment pattern data are prestored in a memory for each accompaniment style such as that of a march or rock, detection is made of an amount indicative of a performance state of a keyboard such as a key touch or key depression time on the keyboard, and different accompaniment pattern data belonging to the same accompaniment style are read out in accordance with the detected performance state so as to change automatic accompaniment patterns.
Further, in those devices disclosed in for example Japanese Patent Laid-open Publication Nos. Hei 2-71293, Hei 2-71294, Hei 2-71295 and Hei 2-71296, detection is made of a keyboard performance state such as a key touch or key depression interval, and the detected keyboard performance state is compared with a predetermined reference value. When the keyboard performance state exceeds the reference value, an accompaniment pattern data to be read out from an accompaniment data memory is changed. With this arrangement, an accompaniment pattern is automatically changed, so that an accompaniment tone suitable for a played music piece can be produced and also undesirable monotonousness in the accompaniment tone can be avoided.
However, the prior art devices are disadvantageous in that the accompaniment pattern tends to change too greatly as the keyboard performance state changes greatly and this creates unnatural flow of the automatic accompaniment. Further, since the reference value with which the keyboard performance state is compared is a constant value, and thus a detected keyboard performance state is caused to change in response to the change in the mood of a music piece played, player's habit or inclination, or in a tone color of a played tone, the accompaniment patterns tend to be changed too frequently in the course of playing of the music piece, or otherwise the accompaniment patterns tend to be changed too rarely. This creates the problem that the accompaniment pattern change can not be effected at a proper frequency.